Dual compression format digital video production system

ABSTRACT

An audio/video production system is implemented on a PC-based platform, preferably utilizing various forms of removable magnetic, optical, or magneto-optical storage media. Specially modified cameras or other sources provide digitally data-compressed audio and video program materials in two formats, a first format having a higher data-compression ratio and intended for use in off-line systems to develop edit decision lists, and a second format having a lower data-compression ratio and intended for use in on-line editing and to produce the final representations of the programs. Off-line editing decisions may thus be developed on a PC using removable storage media, and final representations of the programs may be produced on-line in accordance with stationary-head or rotary-head digital-tape-based formats, such as DAT, 6-mm or 8-mm tapes. In an alternative embodiment, automatic and unattended editing, or extended program playback of more than 40 hours duration of digital video, is available.

REFERENCE TO RELATED APPLICATIONS

More than one reissue application has been filed for the reissue ofpatent application Ser. No. 09/900,784. The reissue applications areapplication Ser. Nos. 11/003,580, filed Dec. 3, 2004 (the presentapplication), 11/003,834, filed Dec. 3, 2004, 11/003,576, filed Dec. 3,2004, and 11/003,579, filed Dec. 3, 2004, all of which are continuationreissues of patent application Ser. No. 09/900,784. This is acontinuation of U.S. patent application Ser. No. 09/900,784, filed Jul.6, 2001, now U.S. Pat. No. Re. 42,020, which is a continuation of U.S.reissue application Ser. No. 09/016,777, filed Jan. 30, 1998, now U.S.Pat. No. RE37,342, which is a reissue of U.S. Pat. No. 5,488,433, whichis a continuation-in-part of U.S. application Ser. No. 08/298,104, filedAug. 30, 1994, now U.S. Pat. No. 5,537,157, and U.S. application Ser.No. 08/050,861, filed Apr. 21, 1993, now patented, U.S. Pat. No.5,450,140, the entire contents of all of which are incorporated hereinby reference.

FIELD OF THE INVENTION

This invention relates generally to video recording systems associatedwith the editing of program materials, and, more particularly, to asystem that takes advantage of a PC-based platform for performingnon-linear editing functions.

BACKGROUND OF THE INVENTION

Traditional video editing systems are generally divided into twocategories: linear and non-linear. Linear editing systems are generallyintegrated with tape-based program storage, while non-linear editingsystems are associated more closely with disk-based storage media,wherein random-access storage more easily may be implemented. Thetypical linear editing system is implemented with one of the many“broadcast quality” videotape recording formats. The choices for analogrecorders include, among others, 1″ C-format, Betacam, Betacam-SP, ¾″U-matic, U-matic-SP, S-VHS, and Hi-8. The choices for digital recordersinclude, among others, D-1, D-2, D-3, D-5, DCT, and Digital Betacam.Each of these recording formats is incompatible with any other format,and all require sophisticated system facilities, includingsynchronization systems, edit controllers, audio and video switchers andprocessors, digital video effects (DVE) systems, character generators,and other equipment. This, in turn, requires extensive physical plantfacilities for electric power, air conditioning and air filtration,storage space, and maintenance equipment. Furthermore, large operationaland maintenance staffs are required to keep the equipment in goodworking order. However, recording duration capacity for these types ofvideotape recorders ranges up to three hours or more, making themuniquely valuable for many applications, such as program distribution,archival storage, and as master program sources for mass duplication ofvideos for the home video market.

In contrast, non-linear systems are based on optical discs, oralternatively, on magnetic or magneto-optical disks. Because of therelatively high cost of these storage media when long-duration recordingperiods are required, such systems are relegated to use as off-lineediting systems applied to the preparation of edit decision lists (EDLs)for use in edit suites incorporating linear editing systems. However,the rapid random-access features and editing ease are valuable for shortprograms.

As currently implemented by many manufacturers (such as AVID andvideoCube), PC-based hard disk storage is very expensive. If equippedwith 10 GB of storage capacity, the system, in practice, is utilized ina two-step process. First, the original unedited program material isdigitized at a high data-compression ratio to provide representativepictures for use in an off-line editing environment, whereby theoperator may develop an EDL. This EDL then is used to perform therequired editing, using program materials that have been digitized andstored at much lower data-compression ratios. Because these twodigitizing steps must be performed in real time, this is an expensive,time-consuming process which requires well-trained and expensiveoperational and engineering personnel.

SUMMARY OF THE INVENTION

It is an object of the invention to integrate the most valuable featuresof linear and non-linear editing system approaches.

It is another object of the invention to provide capabilities forautomatic unattended editing from edit decision lists developed on anoff-line editing system.

It is yet another object of the invention to provide a PC-based digitalvideo recorder for applications such as broadcast television playback,video duplication source-master playback, or other related applications.

A further object of the invention is to provide extended playback of 40hours or more of digital video programming, for cable television orother uses.

The present invention achieves these and other objectives by providing aPC-based audio/video production system which addresses the problem ofproviding inexpensive alternatives to the large, expensive edit suitescurrently in common use. Digital program source materials, produced byspecially modified cameras or other sources, provide data-compressedaudio and video program materials in two formats having matchededit-time-code identification. A first format having a higherdata-compression ratio and intended for use in an off-line editingsystem is used to develop an edit decision list, and a second formathaving a lower data-compression ratio is used in an on-line editingsystem for the production of a final representation of the program. Assuch, off-line editing decisions may be developed on a PC, including aportable PC, using removable storage media, and final representations ofthe programs may be implemented on a stationary-head or rotary-headdigital-tape-based format, such as DAT, 6-mm or 8-mm.

By employing one of several new, small, inexpensive storage media suchas PCMCIA-based disk drives, and by utilizing data-compressiontechnology, the off-line editing capabilities are achieved in aneconomical system, with the digital-tape-based formats providingbroadcast-quality required even for demanding applications. Recordingduration capacity for these media is 60 to 120 minutes or longer forconventional NTSC or PAL video formats, and a natural extension to HDTVformats (with comparable program duration capacity) is achieved ascommercial availability of storage media having higher recordingdensities becomes economically practical. Where compatibility to filmmaterials is desirable, operation of the various system components at 24frames-per-second is implemented.

A method of producing a final video program according to the inventiontherefore includes the steps of providing program source materials infirst and second digital formats, the first format being characterizedin having a higher data compression ratio than the second; recording thematerials in the first and second formats, respectively, onto first andsecond removable storage media along with correlated edit-time-codeinformation in each case; interfacing the first storage medium to anoff-line video editing system to develop an edit decision list;interfacing the second storage medium to an on-line video editingsystem; transferring the edit decision list developed in conjunctionwith the off-line video editing system to the on-line video editingsystem; and editing the materials in the second format on the secondstorage medium, in accordance with the edit decision list, to produce afinal video program.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of a portable dual-format digital videorecorder optionally implemented as part of a camcorder system;

FIG. 2 is a functional block diagram of a dual-format digital videorecorder;

FIG. 3 is an oblique representation of an off-line digital video editingsystem implemented with a PC-based edit controller having provisions foraccepting removable storage media; and

FIG. 4 is a block diagram of an on-line digital video editing systemimplemented with a PC-based edit controller having provisions foraccepting removable storage media.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a portable dual-format digital video recorder according tothe invention, optionally implemented as part of a camcorder system. Alens 2 and viewfinder 4 are mounted on the body of a camera frame. Theusual optical-splitter, CCD sensors and driver circuitry, and digitalsignal processing circuitry are located at 6, with optional battery-packcapability being shown at 10. The various analog and digital outputsignals and any input audio, video, or control signals, all showngenerally at 16, are interfaced through appropriate connectors disposedon the rear-panel 12 and sub-panel 14. Provisions are included as shownfor the input of analog audio signals, and for the output of both analogand digital audio signals. Preferably fiber-optic cabling is employed asa signal-carrying medium.

The internal video recording facilities are comprised of two parts.First, a lower data-compression-ratio digital audio/video signal isrecorded on a stationary-head or rotary-head digital data tape recorder(such as quarter-inch cartridge, half-inch cartridge, DAT, 6-mm or 8-mm)in the removable-tape transport 18, intended for utilization in anoff-line video editing system, described herein below. Simultaneously, asecond digital audio/video signal having a higher data-compression ratiois recorded on a removable storage media unit 20. This removable storagemedium is intended for utilization in an off-line video editing system,also described herein below. In practice, this removable storage mediummay be implemented by any of several well known technologies, such asmagnetic or magneto-optical disks, optical discs, or semiconductormemory modules. The two signal recording media implemented in the twoparts of the internal video recording facilities may record the audioand video signals in separated form, or alternatively may be implementedby any of several well-known systems for interleaved audio/video data,such as the audio/video interleave (“AVI”) system of MicrosoftCorporation, the “M-Power” technique offered by Hewlett-Packard, orother systems.

Examples of removable storage media include PCMCIA-based removable diskdrives (currently available with capacities of 420 MBytes, and soon tobe available with capacities as high as 1 GByte) and 8-mm. tapecassettes (currently available with capacity of 20 GB, and soon to beavailable with capacities as high as 80 GB). At a data-compression ratioof 50:1, 420 MBytes will store approximately 75 minutes of programmaterial (in NTSC format using an image dimension in pixels of 320×240for off-line editing), and at a data-compression ratio of 5:1, 20 GBalso will store approximately 60 minutes of program material. When thenewer 50 GB or 80 GB tapes become available, these tapes will be capableof storing either four hours of programming in NTSC or PAL format, ortwo hours in an HDTV format, making them practical for use in thoseapplications currently allocated to linear editing equipment, asdescribed above. Alternatively, using the currently available MPEG-2data compression with a ratio of 20:1, a 20 GB tape will accommodatefour hours of NTSC or PAL recording (or one hour of HDTV); an 80 GB tapewill accommodate 16 hours of NTSC or PAL recording (or four hours forHDTV). Where compatibility to film materials is desirable, operation ofthe various system components at 24 frames-per-second is implemented.

FIG. 2 is a functional diagram of a storage-device-based digitalrecorder according to the invention, either employed in a video camera,or implemented separately in editing and production facilities. Asshown, a removable hard disk drive 70 and a digital tape drive 88 areinterfaced through an interface bus controller 72. Such a systemachieves data transfer rates of 10 MB/sec, and higher rates on these orother data storage devices, such as high-capacity removable memorymodules, is anticipated. In practice, alternative methods of storagesuch as optical or magneto-optical drives could be utilized, preferablybased on various interface bus standards such as SCSI-2 or PCMCIA. Inall cases, however, in order to ensure compatibility with downstreamediting facilities, both of the removable media for drives 70 and 88should be recorded with identical or at least correlated edit-time-codeinformation, so that edit lists developed from one storage medium willproduce the same results when applied to the program material recordedsimultaneously on the other storage medium.

Microprocessor 74, through user interface provisions 75 (such askeyboards, touch-screens, etc.) controls the 64-bit or wider data bus80, which integrates the various components. Currently availablemicroprocessors include the Alpha 21064 by Digital EquipmentCorporation, and the MIPS R4400 by MIPS Technologies, Inc. Futureimplementations might rely on the already announced P6 by Intel Corp. orthe PowerPC 620. An alternative architecture may be implemented usingmultiple processors working in parallel to increase the effective framerate. The PCI data bus, for example, is capable of sustained datatransfer rates of 100 MB/sec. A ROM 76 is used for fixed programstorage. The RAM 78 preferably has the capacity to function as a buffer,representing 25 seconds or more of live NTSC video in 4:2:2 format, toenable “hot-swapping” of removable media without interruption of theinput video signal during recording or alternatively the output videosignal during playback. Graphics processor 82 represents dedicatedhardware which performs the various manipulations required to processinput video signals 84 and to output the video signals 86. Althoughshown as Y/R-Y/B-Y format, either the inputs or outputs, or both, may beconfigured in alternative formats, such as RGB, YIQ, YUV or othercommonly used alternatives.

While a software-based implementation of the data compression ispossible, a hardware-based implementation is preferred, with the systememploying, for the tape-based drives, a data-compression ratio of 5:1for conventional signals (NTSC/PAL) and a 10:1 data-compression ratiofor HDTV signals. For the hard-disk drive, a data-compression ratio of50:1 is preferably utilized. Examples of the many available options forthis data compression function include the currently available AppleQuickTime system, fractal compression, MPEG-1 (for off-lineapplications) and Motion-JPEG (for on-line applications). In manyapplications, MPEG-2 data compression will be suitable for on-lineediting. Audio signals may be included within the data stream, asproposed in the several systems for digital television transmissionalready under evaluation by the Federal Communications Commission, or byone of the methods available for integrating audio and video signalsused in multi-media recording schemes, such as the Microsoft “.AVI”(Audio/Video Interleave) file format. As an alternative, an independentsystem for recording audio signals may be implemented, either byemploying separate digital recording provisions controlled by the samesystem and electronics, or by implementing completely separate equipmentexternal to the camera system described above.

FIG. 3 shows an off-line digital video editing system, implemented witha PC-based edit controller having provisions for accepting materials inthe form of removable storage media. The controller 102 is preferably ofconventional design, but operates at least at the level of current IntelPentium or high-level “486” processors. The unit is equipped with acolor display, and preferably includes a PCI internal bus structure, andprovisions for interfacing with a removable PCMCIA storage card 104. Inone embodiment this card 104 is implemented with magnetic ormagneto-optical disks, or with an optical disc unit. Alternatively, astand-alone external data storage unit (not shown) could be interfacedthrough the PCMCIA facilities, or by way of an SCSI-type interface.

As an optional feature, a PCMCIA expansion adapter 106 may be provided,so that a plurality of PCMCIA cards or PCMCIA devices 108 may beaccessed conveniently through a single PCMCIA slot on the PC, as shown.This expansion adapter is provided with internal selection andmultiplexing circuitry, so that each plug-in card or device may beaccessed independently and without interference with any other card ordevice in the expansion adapter. The selection may be performed byemploying techniques well-known in the art, such as the addressingschemes utilized for SCSI or GPIB data busses. Since a single 420 MBytePCMCIA card module is capable of holding 75 minutes of programmingmaterial with image dimensions in pixels of 320×240, 4:2:2 sampling anda 50:1 data compression ratio, an expansion adapter equipped with tenPCMCIA slots and plug-in cards is capable of providing ten hours oforiginal program material, and this programming capacity is capable ofbeing further expanded with other types of PCMCIA-compatible devices. Asa further option, a custom-designed PC could be provided with multiplePCMCIA slots to accept a plurality of storage devices without the needfor an external expansion adapter.

In operation, the off-line digital video editing system PC is used toedit and combine the materials stored on various data-storage devices,producing an edit decision list which then may be utilized by an on-lineediting system. The availability of multiple storage devices enables theoperator to rehearse and then confirm “A/B-roll” edits with only twostorage devices, and “A/B/C-roll” edits with three storage devices. Whenequipped with expansion provisions or additional SCSI-bus devices, thesystem is capable of controlling the various storage devices so as toproduce highly complicated sequences in a convenient and timely manner.While the lower-quality (higher data-compression ratio) programmaterials are utilized only for determining the edit points (editdecision list) for the program, the off-line editing system describedherein below is capable of producing the final edited version of theprogram with high-quality results in accordance with the preferredembodiment.

The versatility of the system may be further enhanced if planning forthe program is begun by providing script and staging information to thecomputer in advance of editing, or even in advance of filming or tapingthe original production. The script may be provided as a simple textfile, or as a formatted word processor file, such as used in“WordPerfect” or “Word for Windows”. As an alternative, the file may beof a custom format, as is commonly used by professional scriptwriters.This script and staging information is then reformatted to includespecific commands, such as when to switch camera coverage to aparticular actor, or the choice of a particular camera angle. Furtherdetails may now be included, such as the ability to identify close-upcamera coverage, or points at which specific visual special effects(such as split-screen views or chroma-keyed backgrounds) or soundeffects are to be incorporated. The modified script file is then used toguide the operator of the off-line editing system in making editdecisions to match the program materials to the script, to make anymodifications to the script that are necessitated by the circumstancesof the taping, or to take advantage of any unforeseen artisticopportunities presented by the actual taped materials.

In addition, it is common practice in broadcast-television news studiosto use remotely controlled cameras to telecast the live programs. Thesecameras are mounted on motorized bases which are capable of moving thecameras to any desired position on the stage, within the physical limitsimposed by the stage itself (such as the length of the camera cables orthe clearance available for cameras to move relative to each other onthe stage). The zoom-lenses, pan-tilt mounts, and camera electroniccontrol settings are manipulated through the camera remote-controlfacilities, which may include either separate electronic control panelsor alternatively computer interfaces with appropriate control software,such as the unit described by Washino, U.S. Pat. No. 5,325,202. Bycoupling the software script materials to instructions for control ofthe camera movements, the capabilities of all of these systems may beoptimized. The modified script file must be prepared before the actualtaping occurs, however, and should include the physical layout of thesets and props for each scene.

The staging information described herein above, is identified by specialcamera-remote-control software, and the camera control operator isprovided with a graphical interface which depicts the layout of the setand the “blocked” positions of the actors and props for a given scene.This system preferably also includes a user interface (such as atouch-screen or a mouse) to enable the camera control operator toprogram the cameras to be in the correct location, and to have thecorrect zoom-lens and pan-tilt positions, to capture the scene asdesired, as described in co-pending application U.S. Ser. No.08/050,861. At this time, the operator optionally may add information tocontrol automated lighting systems, which are well-known in the art ofthe film, video, and stage production. This enhanced version of themodified script file is then used to direct camera actions during theactual taping of the scenes, and is further modified as part of theoff-line editing process as the EDL is developed, as described above, inaccordance with the invention.

An on-line digital video editing system is depicted in block-diagramform in FIG. 4. The functional operation of the editing system followsthat of the digital video editing system disclosed in FIG. 2, or in analternative embodiment, may be implemented in a more sophisticated form,as described in our co-pending application “Multi-Format Audio/VideoProduction System,” U.S. application Ser. No. 08/298,104 filed Aug. 30,1994. This system is implemented with a PC-based edit controller 206having separate provisions for accepting removable storage media. In thepreferred embodiment, the digital video tapes recorded by the system ofFIG. 2 are installed in a tape-storage “jukebox” 208 for easy accessduring editing. Such tape cassette handling devices are well-known inthe art of computer data storage, and are generally utilized for databack-up applications or for archival storage.

The edits incorporated into the edit decision list are utilized tosequence the various digital tapes so as to assemble a recording of thedesired program materials into a final finished product, which is thenrecorded on the videotape recorder 202. This video recorder may beimplemented as any of the commonly used choices for analog recorders,including, among others, 1″ C-format, Betacam, Betacam-SP, U-matic-SP,and Hi-8. If implemented as a digital recorder, the available choicesinclude, among others, D-1, D-2, D-3, D-5, DCT, and Digital Betacam.Furthermore, the final format could be another digital data tape such asthe type used for program source material or any other removable storagemedia. Since the time-code identification numbers on the removable mediaof the off-line system correlate with those utilized in the on-linesystem, no conversion or adaptation of the edit decision list is needed.The video monitor 204 is used to manipulate the windows-based editsystem control software, and to view the program materials as the editprocess proceeds. This process will be essentially automatic, as all ofthe necessary decisions already have been made in the off-line editingprocess as described above. In addition, this is an appropriate time foradding digital video effects to the program or to implement any specialeffects included in the program script.

The invention may be used for other applications limited torecord/playback, without implementing the full range of editingfeatures. For example, in applications such as master playback for videoduplication, the program master tape must be played, rewound to thebeginning, and then restarted, on a repeating cycle. In facilitiesemploying a conventional video tape recorder, this represents a greatdeal of physical stress on the program master tape, thereby requiring alarge number of copies of this master tape when many production runs arerequired to complete an order. In addition, some production time is lostdue to the rewinding process itself. In a disk-based application of thesystem disclosed herein, there is no significant deterioration of themaster program even in repeated usage, and it is possible to beginplaying a program at any point desired, with essentially no delay due nocueing the program media to the physical location containing that partof the recorded program. In order to provide the necessary recordingtime duration, additional hard-disk drives would be added to achieve therequired playback duration. Based on an MPEG-2 data-compression ratio of20:1 (with a 4:2:2 recording system for NTSC signals), two hours ofdigital video would require approximately 8 GB of disk storage capacity.Disk-drives offering capacity of 9 GB are currently available, and untilremovable media achieve comparable levels, a program would accordinglybe loaded into internal or external disk-storage units from the requirednumber of removable media units.

The invention may also be employed as a playback unit for cabletelevision usage or other extended-playing time applications. By addingas many “juke-box” units as desired, it is a simple matter to extend theplayback time capability of the system, with each “juke-box” providingapproximately 40 hours of digital video playback. By fully utilizing theRAM-based audio/video buffering capabilities discussed with reference toFIG. 2, it is possible to supply digital video playback on a continuousbasis by changing the tape storage cassettes or cartridges “on-the-fly”while video playback proceeds. If provided with computer-readableidentification codes on each cassette or cartridge, the computer is ableto locate the “juke-box” and the particular physical storage slotcontaining program materials that previously have be scheduled forplayback. Identification and library management systems of this type arewell-known in the art, and are in common usage implemented as“cart-machines” employed for playback of commercial advertisements orother program materials at broadcast stations. In addition, playback atany frame rate or television system standard would be available, inaccordance with our co-pending U.S. application Ser. No. 08/298,104filed Aug. 30, 1994.

The versatility of the Digital Video Production System may be enhancedfurther, if planning for the program is begun by providing script andstaging information to the computer in advance of editing, or even inadvance of filming or taping the original production. Computer softwarehaving access to the script materials will enable the operator to matchthe scenes to the recorded video materials quickly, thereby speeding theediting process. In addition, it is common practice inbroadcast-television news studios to use remotely-controlled cameras totelecast the live programs. By coupling the software script materials toinstructions for control of the camera movements, the capabilities ofall of these systems will be optimized.

1. A digital audio/video production system adapted for use with anon-line video editing facility, the production system comprising: adigital video recorder capable of simultaneously recording informationrepresentative of the same program source material, including correlatededit-time-code information, onto first and second removable storagemedia in first and second formats, respectively, the information in thefirst format being data-compressed relative to the information in thesecond format; a programmed personal computer configured to receive thefirst removable storage medium, enabling an operator to edit theinformation representative of the program source material in the firstformat in off-line fashion so as to develop an edit decision list; andmeans to transfer the edit decision list to an on-line video editingfacility, the on-line editing facility being further configured toreceive the second removable storage medium, whereby an operator of theon-line facility may edit the program source material in the secondformat using the edit decision list to create a final video production.2. The digital video production system of claim 1, wherein theinformation in the second format is non-compressed.
 3. The digital videoproduction system of claim 1, wherein the digital video recorder formspart of a camcorder.
 4. The digital video production system of claim 1,wherein the first removable medium is a magnetic hard disk.
 5. Thedigital video production system of claim 1, wherein the first removablemedium is an optical disk.
 6. The digital video production system ofclaim 1, wherein the first removable medium is a magneto-optical disk.7. The digital video production system of claim 1, wherein the secondremovable medium is a tape drive.
 8. The digital video production systemof claim 1, including digital audio and video program data which areinterleaved.
 9. The digital video production system of claim 1, themeans to transfer the edit decision list to the on-line video editingfacility including means to record the edit decision list onto a thirdremovable storage medium.
 10. The method of producing a final videoprogram, comprising the steps of: providing video program sourcematerial in first and second digital formats, the material in the firstformat being compressed relative to the material in the second format;recording the material in the first and second formats, respectively,onto first and second removable storage media along with correlatededit-time-code information; interfacing the first storage medium to anoff-line video editing system to develop edit decision information;transferring the edit decision list to an on-line video editing system;accessing the program material in the second storage medium using theon-line video editing system; and editing the material in the secondformat on the second storage medium in accordance with the edit decisionlist to produce a final video program.
 11. The method of claim 10, thesecond format being a non-compressed format.
 12. A digital videoproduction system adapted to deliver program material and anaccompanying edit decision list to an on-line video editing facility forthe purpose of creating a final program, the system comprising: digitalvideo recording apparatus, including: an input to receive a videoprogram, means to digitally compress the program in accordance with morethan one compression ratio, an interface to a first removable storagemedium, an interface to a second removable storage medium, and means tosimultaneously record the video program onto the first removable storagemedium at a first compression ratio and onto the second removablestorage medium at a second compression ratio, the first compressionratio being greater than the second; and an off-line digital videoediting system, including: an interface to receive the first removablestorage medium. a display to review portions of the video program,enabling a user to make edit decisions concerning the program, and aninterface to a third removable storage medium to store a list of theedit decisions, whereby an on-line video editing facility, uponreceiving the second and third storage medium, may be used to produce afinal, edited version of the program in accordance with the decisionlist.
 13. The digital video production system of claim 12, wherein thesecond compression ratio is zero.
 14. The digital video productionsystem of claim 12, wherein the off-line digital video editing systemforms part of a programmed personal computer.
 15. The digital videoproduction system of claim 12, wherein the digital video recorder formspart of a camcorder.
 16. The digital video production system of claim12, wherein the first removable medium is a magnetic disk drive.
 17. Thedigital video production system of claim 12, wherein the first removablemedium is an optical disk.
 18. The digital video production system ofclaim 12, wherein the first removable medium is a magneto-optical disk.19. The digital video production system of claim 12, wherein the secondremovable medium is a tape drive.
 20. The digital video productionsystem of claim 12, including interleaved digital audio and videoprogram data are interleaved.
 21. The digital video production system ofclaim 12, wherein the program includes separately recorded audio andvideo portions.
 22. A digital video recording apparatus adapted for usewith an on-line video editing facility and a personal computerconfigured to perform off-line editing, including edit-list development,the apparatus comprising: a camera outputting information representativeof a video program; means to digitally compress the program informationat a plurality of compression ratios; a removable disk drive to store ahighly compressed version of the program information suitable foroff-line editing using the personal computer; and a removable tape driveto store a less compressed version of the program information suitablefor on-line editing; both versions of the program being stored withcorrelated edit-time-code information, thereby enabling the on-lineediting to use the edit list developed during off-line editing.
 23. Thedigital video recording apparatus of claim 22, wherein the camera, meansto digitally compress the program at a plurality of compression ratios,removable disk drive, and removable tape drive are all integral to acamcorder.
 24. A digital audio/video production system, comprising: (a)digital video recording apparatus, including: an input to receive avideo program, first and second removable digital storage media, andmeans to simultaneously record the program, including correlatededit-time-code information, onto the first and second removable storagemedia in first and second formats, respectively, the first format beingdata-compressed relative to the information in the second format; (b) afirst video editing system, including: means to receive the firstremovable storage medium, and controls enabling an operator to edit theprogram in the first format and develop a set of edit decisiondirectives; and (c) a second video editing system, including: means toreceive the second removable storage medium, means to receive the editdecision directives, and means to edit the program information in thesecond format in accordance with the edit decision directives to createa final video production.
 25. The digital audio/video production systemof claim 24, wherein the digital video recording apparatus includesmeans to receive a plurality of the first removable storage media. 26.The digital audio/video production system of claim 24, wherein thesecond video editing system includes means to receive a plurality of thesecond removable storage media, wherein the edit decision directivebeing applicable to all of the second removable storage media received.27. The digital audio/video production system of claim 26, wherein thedigital video recording apparatus forms part of a camcorder.
 28. Thedigital audio/video production system of claim 26, wherein the firstvideo editing system forms part of a programmed personal computer. 29.The digital audio/video production system of claim 26, wherein the firstremovable digital storage medium is a magnetic disk.
 30. The digitalaudio/video production system of claim 26, wherein the first removabledigital storage medium is an optical disk.
 31. The digital audio/videoproduction system of claim 26, wherein the first removable digitalstorage medium is a magneto-optical disk.
 32. The digital audio/videoproduction system of claim 26, wherein the first removable digitalstorage medium is a semiconductor memory.
 33. The digital audio/videoproduction system of claim 24, wherein the second removable digitalstorage medium is a magnetic tape.
 34. A video production method,comprising the steps of: simultaneously recording informationrepresentative of a video program, plus correlated edit-time-codeinformation, onto first and second removable digital storage media infirst and second formats, respectively, the program information in thefirst format being data-compressed relative to the program informationin the second format; receiving the first removable storage medium at afirst video editing facility and editing the program information at thefirst facility in the first format to develop a see of edit decisiondirectives based upon the edit-mime-code information; and receiving thesecond removable storage medium and edit decision directives at a secondvideo editing facility and editing the program information at the secondfacility in the second format in accordance with the edit decisiondirectives so as to create a final video production.
 35. The videoproduction method of claim 34, further including the step of recordingthe final video production onto a third removable storage medium at thesecond video editing facility.
 36. The video production method of claim34, further including the step of outputting the final video productionas the program information is edited in the second format in accordancewith the edit decision directives.
 37. The video production method ofclaim 34, wherein the step of editing the program information at thesecond facility further includes the step of adding audio specialeffects in the final video production.
 38. The video production methodof claim 34, wherein the step of editing the program information at thesecond facility further includes the step of adding video specialeffects in the final video production.
 39. The video production methodof claim 38, wherein the step of adding video special effects includesthe step of adding titling.
 40. A dual format digital video recordingsystem for recording a program having audiovisual content, comprising: afirst digital storage medium; a second digital storage medium; a firstdigital interface associated with the first digital storage medium forreceiving a first signal representing the audiovisual content in a firstcompressed, digital format and edit-time-code information, wherein theaudiovisual content in the first compressed, digital format and theedit-time-code information are recorded onto the first digital storagemedium; a second interface associated with the second digital storagemedium for receiving a second signal representing the audiovisualcontent in a second compressed, digital format and edit-time-codeinformation wherein the audiovisual content in the second compressed,digital format and the edit-time-code information are recorded onto thesecond digital storage medium; wherein the edit-time-code informationfor the audiovisual content in the first compressed, digital format andthe edit-time code for the audiovisual content in the second compressed,digital format are correlated; wherein the audiovisual content in thefirst compressed, digital format is more compressed than the audiovisualcontent in the second compressed, digital format; and wherein theaudiovisual content in the first compressed, digital format is recordedsimultaneously with the audiovisual content in the second compressed,digital format.
 41. The dual format digital video recording system ofclaim 40, wherein the first digital storage medium is a removablestorage medium.
 42. The dual format digital video recording system ofclaim 40, wherein the second digital storage medium is a removablestorage medium.
 43. The dual format digital video recording system ofclaim 40, wherein the audiovisual content in the first and secondcompressed, digital format comprises a frame rate of substantially 24frames per second.
 44. The dual format digital video recording system ofclaim 40, wherein the first signal representing the audiovisual contentin a first compressed, digital format and the second signal representingthe audiovisual content in a second compressed, digital format comprisesa video program, and wherein a complete copy of the video program isstored on the first digital storage medium and a complete copy of theprogram is stored on the second digital storage medium.
 45. The dualformat digital video recording system of claim 40, wherein the digitalvideo recording system forms part of a camcorder.
 46. The dual formatdigital video recording system of claim 40, further including randomaccess memory (RAM) for temporarily storing a portion of the audiovisualcontent in the first compressed, digital format.
 47. The dual formatdigital video recording system of claim 46, wherein the first digitalstorage medium is removable and wherein the first digital storage mediumis hot-swappable from the system.
 48. A dual format digital videorecording method for recording a program having audiovisual content,comprising: providing a first signal representing the audiovisualcontent in a first compressed, digital format and edit-time-codeinformation; providing a second signal representing the audiovisualcontent in a second compressed, digital format and edit-time-codeinformation, wherein the audiovisual content in the first compressed,digital format is more compressed than the audiovisual content in thesecond compressed, digital format and wherein the edit-time-codeinformation for the audiovisual content in the first compressed, digitalformat and the edit-time code for the audiovisual content in the secondcompressed, digital format are correlated; and simultaneously recordingthe audiovisual content in the first compressed, digital format with itsedit-time-code information and the audiovisual content in the secondcompressed, digital format with its edit-time-code information.
 49. Thedual format digital video recording method of claim 48, wherein theaudiovisual content in the first compressed, digital format and itsedit-time-code information are recorded onto a first digital storagemedium and wherein the audiovisual content in the second compressed,digital format and its edit-time-code information are recorded onto asecond digital storage medium.
 50. The dual format digital videorecording method of claim 49, wherein the first and second digitalstorage media are removable.
 51. The dual format digital video recordingmethod of claim 48, wherein the audiovisual content in the first andsecond compressed, digital format comprises a frame rate ofsubstantially 24 frames per second.
 52. The dual format digital videorecording method of claim 49, wherein the first signal representing theaudiovisual content in a first compressed, digital format and the secondsignal representing the audiovisual content in a second compressed,digital format comprises a video program, and wherein a complete copy ofthe video program is stored on the first digital storage medium and acomplete copy of the program is stored on the second digital storagemedium.
 53. The dual format digital video recording method of claim 49,wherein the first and second digital storage media are part of acamcorder.
 54. The dual format digital video recording method of claim48, further including temporarily storing a portion of the audiovisualcontent in the first compressed, digital format on random access memory(RAM).
 55. The dual format digital video recording method of claim 54,wherein the first digital storage medium is removable and furtherincluding hot-swapping the first digital storage medium.